Endocrine System Flashcards
Endocrine System Functions (4)
1) Communication 2) Homeostasis 3) Function by releasing chemical messengers(hormones) into BLOOD 4) works closely with nervous system(neuroendocrine system
Hormones
Chemical messenger released by Glands into BLOOD and bind receptors on TARGET cells (very specific)
3 General Stimulation mechanisms
1) Neural (stim by autonomic neurons) 2) Hormonal 3) Humoral( stim by substances (glucose; ion ect)
2 Main Types of Hormones
1) Peptide (made from amino acids/proteins 2) Steroid (made from fat/ lipids
Stimulate DNA in nucleus (steps)
Steroid and thyroid hormones(lipids) 1: diffuse through the cell membrane(lipid bilayer) 2) bind receptors in cytoplasm or nucleus 3) stimulates protein synthesis by accessing DNA 4) New proteins cause response
Activate 2nd Messenger
Most peptide hormones: 1) Bind receptor on cell membrane 2) activates G protein thus activating 2nd messenger activating ENZYME causing a response (Cyclic-AMP - most common)
Negative Vs Positive feedback loops
Negative Feedback most common stop release in a given window(thermostat) Positive stimulation causes to make more and more. Aka Breast feeding
Hypothalamus (4)
1) Control center for Endocrine System 2) Releases regulatory hormones to ANTERIOR pituitary gland 3) Produces Oxytocin and ADH to be stored in POSTERIOR Pituitary 4) Regulates ANS(adrenal medulla)
Pituitary Gland
Has Anterior and Posterior Portion 2) connected to hypothalamus via infundibulum 3) sella turcica
Anterior pituitary (adenohypophysis)
1) Controlled by hypothalamus(releasing/inhibiting hormones) 2) Hypothalamus hypophyseal portal system
What connects hypothalamus and anterior pituitary gland
Blood Vascular
What connects hypothalamus and posterior pituitary gland
Neurons
7 Major hormone in Anterior Pituitary(adenohypophysis)
1) Growth hormones 2) Thyroid stimulating hormone(TSH) 3) Adrenocorticotropic Hormone (ACTH) 4) Prolactin 5) Follicle -stimulating Hormone(FSH) 6) Luteinizing hormone(LH) 7) Melanocyte stimulating hormone (MSH)
Growth hormone(GH)
Found in Anterior Pituitary ; Aka Somatotropin; stimulates cell growth and division; stimulates LIVER to secrete insulin like growth factors(IGFs); somatomedin
Thyroid stimulating Hormone (TSH)
In the ANT Pituitary stimulates the release of hormones from thyroid gland
Adrenocorticotropic hormone (ACTH)
IN the ANT pituitary; Stim release of hormones from adrenal cortex
Prolactin
In ANT pituitary; Stimulates milk production & mammary gland growth
Follicle-stimulating hormone (FSH)
In ANT Pituitary; Follicle development & estrogen release from ovaries; Sperm production in testes
Luteinizing hormone (LH)
In ANT Pituitary; Stim estrogen release from ovaries & OVULATION Stim testosterone release from testes
Melanocyte-stimulating hormone (MSH)
In ANT Pituitary; Stim rate of melanin release(pigment)
Posterior pituitary (neurohypophysis)
1) Neurosecretory cells in hypothalamus; Hypothalamo-hypophyseal TRACT(bundle of neuron in CNS)
Which Hormones does the Posterior pituitary contain?
Antidiuretic Hormone(ADH) and Oxytocin
What does the paraventricular nucleus make?
Oxytocin
What does the Supraoptic nucleus make
Antidiuretic Hormone(ADH; Vasopressin)
Antidiuretic Hormone(ADH)
Made by the supraorbital nucleus; water retention
Oxytocin Made and do in male vs females
Made in the paraventricular nucleus; Females; contraction o uterus during labor(positive feedback) milk ejection Males: Prostate gland secretion
Isthmus
Crossbar of the Thyroid gland connects lobes
Parts of the Thyroid Gland
1) Follicular cells 2) Parafollicular cells 3)
Follicular cells
In Thyroid Gland; Form follicle (make thyroid hormones) 2) secrete triiodothyronine(T3) and thyroxin (t4) - increase metabolic rate and temperature
Parafollicular cells
Produce Calcitonin; decreases blood calcium by Moving calcium to Astroblast
Thyroid Hormones
Triiodothyronine(T3) and Thyroxine T4
How does Calcitonin decrease calcium in blood
1) move calcium to Astroblast 2) Kidneys excrete more 3) Intestines absorb less
Parathyroid Glands
1) Chief (Principal) cells 2) Oxyphiles cells 3) 4 of them
Chief principle cells secrete
parathyroid hormone when INCREASE blood calcium(osteoclast’s)
Adrenal glands location and parts
Located above kidneys and has a cortex and medulla(looks like a triangle)
Adrenal Cortex
Synthesizes steroid hormones
3 Regions of the adrenal cortex(outside to in)
1) Zona Glomerulosa 2) Zona fasciculata 3) Zona reticularis
Zone glomerulosa
Class of hormones Mineralocorticoids; Aldosterone Hormone(make you retain fluid)
Zona fasciculata
Class of hormones Glucocorticoids; Cortisol Hormone (helps maintain blood glucose levels by stimulates the breakdown of proteins)
Cortisol Hormone
In adrenal gland; Helps maintain blood glucose levels by stimulates the breakdown of proteins) and Stress related hormone (fat storage)
What does Zona reticularis in the Adrenal gland release
DHEA precusory to sex hormones. (testostrogen and estrogen)
Adrenal Glands Medulla (3)
1) Medulla secretes catecholamines 2) Chromaffin cells innervated by sympathetic axons 3)Releases Epinephrine & norepinephrine
Pancreas
Endocrine and exocrine functions Endocrine: Islet of Langerhans(2) Alpha and Beta
Islets of Langerhans (cells and function)
1) Alpha (glucagon- INCREASE blood glucose) 2) Beta (insulin - decreases blood glucose)(transport ion)
Pineal Gland
Posterior Epithalamus 2) Secretes melatonin - Regulates circadian rhythms
Thymus
Superior to heart 2) immune function 3) Stimulates growth in T-Lymphocytes (more in kids)
Ovaries hormones
Release Estrogen and progesterone\
Estrogen Hormone
Female secondary sex characteristics; follicular development; fat deposition in thighs
Progesterone
Important in menstrual cycle
Testes produces?
Testosterone; male secondary sex characteristics; stimulate protein synthesis(like steroids)
Kidneys Secretes
Calcitriol; ERTHROPOIETIN; Renin
Calcitriol
In kidneys; stimulates Ca and phosphate uptake in small intestine
Erythropoietin
Stimulate RBC production( Tour de France cyclists to increase o2 cap)
Heart Releases
Atrial natriuretic peptide
atrial natriuretic peptide
IN heart; stimulates water and sodium excretion
Thyroid Disorders
Graves; Hypothyroidism; Goiters can occur
Graves Disease
Bulging eyeballs(to much thyroid)
Hypothyroidism
To little thyroid (heavy hard time losing weight; colder)
Goiters
Neck swelling from thyroid hypothyroidism from lake of iodine in diet
Growth Hormones disorders
1) Acromegaly 2) Gigantism 3) Pituitary Dwarfism
Acromegaly
To much growth hormone as an adult( larger face and hands)
Gigantism
Excess GH in Childhood( muscle weak for size)
Pituitary Dwarfism
Insufficient GH
Cortisol Hormone Disorders
Cushing disease; Addison disease
Cushing disease
Too much cortisol ( central obesity; moonfaced; buffalo hump)
Addison disease
Too little cortisol( Fatigue weakness weight loss)(JF Kennedy)
Diabetes Mellitus
Fasting blood >= 126 mg/dl; Pre diabetes 100-125 mg/dl
Type 1 Diabetes
Autoimmune disease; beta cells destroyed; insufficient insulin production from pancreas
Type 2 Diabetes
Insulin resistance/ insufficient insulin( can be cured with diet and exercise)